Impact of smoking status and cumulative smoking exposure on tumor recurrence of non-muscle-invasive bladder cancer.

Objective: To investigate the effect of smoking status, cumulative smoking exposure and smoking cessation on the outcomes of patient with non-muscle-invasive bladder cancer (NMIBC).

Methods: We collected smoking data from 484 patients with NMIBC who were treated with transurethral resection (TUR); smoking status was categorized as (never smokers vs current smokers vs former smokers). Cumulative smoking exposure was categorized as high smoking exposure (cigarette index ≥400) versus low smoking exposure (cigarette index <400). Association with outcomes was examined by multivariable analyses after adjusting for the effects of standard clinicopathologic factors, and the Kaplan-Meier method was used to estimate the effect of smoking status and cumulative smoking exposure on RFS.

Results: A total of 168 (34.7 %) patients were never smoker, 121 (25 %) patients were current smokers, and 195 (40.3 %) patients were former smokers. The median follow-up was 25 months. By multivariate analysis, pathological grade (p = 0.013), history of recurrence (p < 0.001), number of tumors (p < 0.001) and size of tumors (p = 0.013) were significantly associated with tumor recurrence; nevertheless, smoking status did not influence tumor recurrence (p = 0.063). Among current and former smokers, cumulative smoking exposure was significantly associated with tumor recurrence (p < 0.001), compared to current smokers, patients with smoking cessation ≥10 years had a lower risk of tumor recurrence [hazard ratio (HR) 0.456, p = 0.007].

Conclusions: Smoking affects the prognosis of patient with NMIBC, which is still controversial; however, among ever smokers, a high cumulative exposure smoking can significantly increase the risk of tumor recurrence. Quitting smoking might be associated with a lower recurrence rate for patients with NMIBC.